Thermostat switch



July 23, 1963 HUFFMAN 3,098,913

THERMQSTAT SWITCH Filed June 29, 1960 s\\\\::\\\ Rif -Will lNVENTOR 1 Jam: I I THUFPMAM.

United States Patent Ofitice Patented July 23, 1963 3,898,913 THERMQSTAT SWITCH John W. Huihnan, Mansfield, Ohio, assignor to Pace, Ina, Mansfield, Ohio, a corporation of Ohio Filed June 29, 1960, Ser. No. 39,520 Claims. (Cl. 200-438) This invention relates to switch constructions and more especially to a switch embodying a thermoresponsive means or element arranged to establish or interrupt an energizing circuit under the influence of heat ambient the thermoresponsive component or element in combination with manually adjustable means for varying the relative position of a switch member in accordance with a temperature to be maintained by operation of the thermoresponsive means.

Control switches of the thermoresponsive type of small compact construction have been utilized for thermic control of heating or cooling appliances adapted to be energized or activated by 110 volt alternating current where the amperage requirements of the appliance are comparatively low. Switches of the so-called stacked switch assemblage of the compact type have not heretofore been used extensively for appliances such as air-conditioners requiring higher voltage and amperage because of inadequate insulation, a factor which is conducive to excessive current leakage especially under humid atmospheric conditions. I

The present invention embraces a switch construction embodying relatively movable current conducting members or switch arms arranged in a compact assemblage in combination with suitable insulation components of a shape and size and in particular positions to minimize the liability of current leakage, thus providing a switch construction suitable for comparatively high voltage and high amperage requirements of an appliance circuit.

An object of the invention is the provision of a switch mechanism of the so-called stacked switch type which is of compact character embodying a thermostat means for controlling current interrupting means and provided with insulation of a character to avoid short circuiting of the switch mechanism irrespective of the relative position of a movable current conducting component actuated by a thermoresponsive means.

Another object of the invention resides in a switch construction associated with a comparatively thin-walled housing of molded resinous material or plastic wherein the housing is fashioned with wall portions which are distortable to admit of assembly of the switch mechanism within the housing and the portions flexed or moved into mechanism retaining position thus avoiding the use of separable means for maintaining or retaining the switch mechanism in the housing.

Further objects and advantages are within the scope of this invention such as relate to the arrangement, operation and function of the related elements of the structure, to various details of construction and to combinations of parts, elements per se, and to economics of manufacture and numerous other features as will be apparent from a consideration of the specification and drawing of a form of the invention, which may be preferred, in which:

FIGURE 1 is a longitudinal sectional View of a combined switch mechanism and housing construction of the invention;

FIGURE 2 is a bottom plan view of the switch construction, the view being taken on the line 2+2 of FIG URE 1;

FIGURE 3 is a transverse sectional view taken substantially on the line 3-3 of FIGURE 1;

FIGURE 4 is a transverse sectional view taken substantially on the line 4-4 of FIGURE 1;

FIGURE 5 is an isometric view of the switch housing construction of the invention;

FIGURE 6 is a top plan view of the housing construction with the switch mechanism assembled therein, the control knob being removed for purposes of illustration;

FIGURE 7 is a detail sectional view taken substantially on the line 7-7 of FIGURE 4;

FIGURE 8 is an enlarged fragmentary detail view of a wall portion of the housing construction illustrating one of the distortable flaps or portions thereof, and

FIGURE 9 is a plan View of the edge region of the portion of the housing shown in FIGURE 8 illustrating the distortable flap in open or switch mechanism receiving position.

The switch mechanism and housing arrangement of the invention is illustrated as embodying a thermoresponsive means for controlling an electrically energizable appliance, but it is to be understood that the arrangement may be utilized for controlling electrical circuits generally Wherever a compact switch mechanism having high insulation characteristics is required or desired.

Referring to the drawings in detail and initially to FIG- URES 1 through 4, there is illustrated a frame portion of an electrically heated or electrically controlled appliance as, for example, an electric iron or the frame portion of an air-conditioning apparatus. For purposes of illustration an electrically energizable element or component 12 is illustrated associated with the frame portion 10 to which electric energy is supplied, the circuit of which is adapted to be controlled by the switch mechanism of the invention. In the embodiment illustrated, the frame portion 10 provides a mounting for the switch mechanism of the invention which, in itself, is of unit construction adapted for mounting upon any suitable support or frame.

The arrangement illustrated in FIGURES 1 through 4 is approximately twice actual size of the switch mechanism. The mechanism of the invention is inclusive of a frame or support means comprising, in the embodiment illustrated, a frame plate 14 and a tubular or sleeve member 16, the plate being provided with an opening to receive a tenon portion 17 of the cylindrical or tubular component 16.

The tubular sleeve 16 provides a support means for several elements of the switch assembly to form a stacked switch. The end region of the tubular component 16 opposite the swaged portion 18 is formed with a circular flange 20 which forms a base upon which components of the switch means are assembled. In assembling the switch components, the components are placed upon the cylindrical or tubular member 16, the frame plate 14 afiixed on the tenon 17 and the portion 18 swaged to provide a unit mechanism. The interior of the 16 is threaded to accommodate a securing bolt 19 for mounting the switch unit upon the appliance frame 10.

The switch mechanism is inclusive of a first switch arm or member 24, a second switch arm or member 28, and a thermoresponsive means or bimetallic element 30 which are mounted by the tubular or cylindrical member 16. The first switch member 24 is provided with a contact 31 and the second switch member 28 provided with a contact 32, the contacts being arranged for cooperation to complete or interrupt a circuit through the electrically energizable unit 12. The components of the switch mechanism are enclosed within a substantially rectangular housing or casing 34 fashioned of molded nonmetallic material such as plastic or moldable resin, the features of the housing being hereinafter described.

One end region of the bimetallic member or thermoresponsive means 30 is provided with an opening through which extends the cylindrical member 16, the bimetallic element being in direct metallic contact with the metal flange 20 formed on the tubular member 16.

Arranged in stacked relation upon the tubular member 16 are circular disks 36, 37 and 38 fashioned of suitable heat resistant insulating material as, for example, lava or ceramic material.

The disk 36 is provided with a cylindrical tenon portion 39 which extends through an opening in the end region of the second switch member 28 and through an opening in a laterally extending terminal member or connector 42 which is in direct metallic contact with the second switch member 28 as shown in FIGURES 1 and 4. The insulating disk or circular member 37 is provided with a cylindrical tenon portion 41 and the end region of the first switch arm or member 24 is provided with an opening to receive the tenon portion 41 on the disk 37 and a second laterally extending terminal member 44 is provided with an opening and is likewise received upon the tenon portion 41 of the insulating disk 37.

The terminal member 44 and the first switch member 24 are in intimate metallic contact for current conducting purposes. One of the terminal members is connected with the electrically energizable component or unit 12, the component 12 being connected with one side of a current supply line, and the other terminal member connected with the other side of a current supply line whereby the switch members 24 and 28 and the contacts 31 and 32 are in series with the electrically energizable unit 12 for completing or interrupting a circuit through the unit 12.

The third insulating disk or circular member 38 is disposed between a metal washer 46 adjacent the frame plate 14 and the upper surface of the terminal member 44 and the tenon portion 41 on the insulating disk 3'7.

It will be apparent from FIGURE 1 that the bimetallic member 30 is spaced a substantial distance from the second switch arm 28 through the medium of the insulating disk 36, the first switch arm 24 is spaced substantially from the second switch arm 28 by the insulating disk 37, and the first switch member spaced substantially from the frame plate 14 through the medium of the third insulating disk 38 and the washer 46.

After these components are assembled on the tubular member 16, an opening in the frame plate 14 receives the tenon portion 17 of the tubular member 16 and the projecting portion of the tenon 17 swaged over the plate 14 as shown at 18 in FIGURE 1. Through this method of assembly, the switch components are maintained in spaced fixed relation.

The bimetallic member 30 is provided with means whereby flexure of the bimetallic member under the influence of heat variations affects or influences the position of the first switch arm or member 24. The distal end region of the bimetallic member 30 is provided with an opening to receive a strut or member 50 formed of lava, ceramic or other heat resistant insulating material, the strut 50 being provided with a flange portion 51 disposed beneath the bimetallic element 30.

The strut 50 is secured in position by means of a metallic clip or securing means 52, the central portion of which engages the flange 51, the tab portions 53 of the clip extending around and engaging upper surface of the bimetallic member as shown in FIGURE 3 to secure the strut 50 in assembled relation with the bimetallic member 30. The upper end 55 of the strut 50 is arranged for engagement with the distal end region of the first switch member 24 to influence the position of the switch member under heat variationis ambient the bimetallic element 30, thus varying the position of the switch member 24 and contact 31 carried thereby.

Manual means is provided for varying or controlling the position of the second switch member or arm 28 and the contact 32 carried thereby for varying the operating temperature range. As particularly shown in FIGURE 1, the frame plate 14 is formed with an opening to receive a tenon portion 60 of a sleeve or fitting 62, the extremity of the tenon being swaged as at 63 into engagement with the frame plate 14 to securely fasten the fitting 62 to the plate.

The fitting 62 extends through an opening 64 formed in the housing 34. The sleeve or fitting 62 is interiorly threaded to accommodate a threaded portion 65 of a shaft 66, the upper end of the shaft being provided with a serrated tenon 68 which receives a manipulating knob or member 74) formed of molded resin or other suitable insulating material, the knob 70 being provided to facilitate rotation of the shaft 66.

The fitting 62 is provided or formed with an abutment or shoulder 72 and the shaft 66 provided with a pin 74 which is adapted to engage the abutment 72 for limiting the extent of rotation of the shaft, this arrangement dethe limits of adjustment of the manually adjustable switch member 28. The end region of the shaft 66 Within the housing 34 is formed with a cup-like recess or socket adapted to receive one end of 1a strut or member 76, the strut '76 being formed of lava, ceramic or other heat resistant material.

The strut 76 extends through an opening in the first switch arm 24 as shown in FIGURE 1. end region of the strut 76 is of tapered or wedge shaped configuration and engages in a depression or recess 78 formed in the lower or second switch member 28. Rotation of the shaft 66, through its threaded engagement with the fitting 62, moves the strut '76 upwardly or downwardly dependent upon lthe direction of rotation of the shaft 66, such movement varying the position of the switch arm 28 and contact 32 carried thereby.

Through this arrangement the temperature at which the appliance or region is to be maintained may be varied by manual rotation of the shaft 66 through the manipulating knob 7i}. 'Ihe energiziatio-n and de-energization of a heating unit 12 to automatically maintain substantially constantly the temperature for which the manual means is adjustable is accomplished through the transfer of heat from the unit 12 to the bimetallic element or thermoresponsive means 30, the flexure or movement of which is transmitted through the member 50 to the first switch arm 24 to vary the position cf the switch arm 24 and the contact 31 in accordance with variations in heat ambient the region of the bimetallic member 30.

The switch arrangement of the invention embodies insulating means adjacent several components of the switch mechanism to enable the use of the switch with comparatively high voltage appliances, such as air-conditioning equipment operating on 220 volt current to prevent or minimize current leakage at increased voltages. The thermostatically controlled switch arm 24 is provided with a comparatively flat strip 80 of insulating material which is secured to the switch member by means of small rivets 82. The strip may be fashioned of textile embedded in resin or plastic having high insulating characteristics. As will be seen from FIGURE 3, the insulating plate or member 80 extends laterally substantial distances beyond the lateral edges of the switch member 24 to minimize the liability of current leakage between the switch member 24 and the frame plate 14 when the thermoresponsive element elevates or moves the switch arm 24 upwardly to a position adjacent the frame plate 14. The switch member 24 is provided with lengthwise extending reinforcing ridges or depressed portions 84 and the switch arm 28 provided with lengthwise extending ridges 86 so that the flexure or hinging action of the switch members 24 and 28 occurs adjacent the region of support of the switch arms by the insulating disks 36 and 37, the ridges 84 and 86 resisting flexure of the switch arms at the regions of the ridges.

As particularly shown in FIGURES 1 and 4, the circular insulating disks 36 and 38 are formed with laterally extending peripheral ridges or flanges 90 extending substantially beyond the circular edge regions of the switch The opp osite members 24 and 28 at the regions of support thereof by the insulating disks.

Through the provisions of the enlarged peripheral regions 90 of the insulating disks 36 and 38 extending beyond the adjacent edge regions of the switch arms 24 and 28, there is less liability of current leakage from the switch arms to the frame plate 14 and to the bimetallic element 30 and the appliance 10.

Through the improved insulation provided by the strip 80 on the switch arm 24 and the peripheral flanges on the insulating disks 36 and 38, the liability of current leakage or loss is greatly reduced enabling the operation of the switch at voltages of 220 or more and providing a high safety factor in preventing short circuit of the current to the frame or support for the switch unit.

The arrangement of the invention includes a switch housing formed of molded plastic as, for example, polystyrene resin or other suitable moldable plastic or resin. In the embodiment illustrated, the housing 34 is of comparatively thin-walled construction comprising side walls 94, 95, end walls 96, 97 and an upper wall 98. The wall 90 is provided with an opening 64 to accommodate the fitting 62.

The housing construction is fashioned with openings or slots in the side walls to accommodate the laterally projecting terminal connectors 42 and 44- which are admitted through slots formed in the housing side walls and the (remainder of the slots closed after assembly by hinged flap portions which may be readily flexed to open and closed positions to facilitate assembly of the switch unit within the housing. With particular reference to FIG- URES 4 and 5, it will be seen that the region 100 of the wall 94 adjacent an opening or slot to accommodate the switch member 4-2 is preferably of lesser thickness than the remainder of the wall 94.

Arranged adjacent the opening or slot in the wall 94 at the region 100 is a flexible portion or flap 102 which is integrally joined to the wall 94 at the region 103, the latter region forming a hinge to permit fiexure or distortion of the flap 102 outwardly to the dotted position shown FIGURES 5 and 9 to accommodate the insertion of the terminal 4-2 into the slot or opening 105 forming a continuation of the slot normally occupied by the distortable portion or flap 102.

The wall 95 is provided with a thin-walled region 107 of lesser thickness than that of the major portion of wall 95 and is formed with a slot normally occupied by a thin-walled portion or flap 108 which is adapted to be distorted or flexed about a hinge region 109 to a laterally extending position as shown in broken lines in FIGURE 5 to accommodate the terminal member 44 in assembling the switch unit in the housing 34.

In assembling the switch unit in the housing 34, the flaps or distortable portions 102 and 100 are first flexed or bent outwardly about the respective hinge regions 103 and 109 at their zones of integral connection with the side walls to laterally extending positions as illustrated in broken lines in FIGURES 5 and 9. The switch unit is inserted in the housing, the shaft 66 and fitting 62 extending through the opening 64 formed in the upper wall 98 of the housing. The switch terminal 44 is admitted into the slot normally occupied by the flap 108 and the switch terminal 42 accommodated in the slot normally occupied by the flap 102.

After the switch unit is inserted in the housing, the flaps 102 and 108 are flexed inwardly about their respective hinge regions until the outer major surfaces of the flaps are substantially in the planes of the outer surfaces of the side walls 94 and 95 as shown in FIGURE 4. The flaps 102 and 108 are of a dimension so as to provide clearance spaces or openings for the terminals 42 and 44 when the flaps are in closed or switch assembled position. Thus, through this arrangement the flaps 102 and 108 provide the securing means for retaining the switch mechanism within the plastic housing 34. It is to be 6 l understood that any suitable moldable plastic or resin having noncurrent-conducting characteristics may be employed for the housing. It is to be understood that the walls of the housing 34 and the flaps 102 and 108 may be of substantially the same thickness if desired, but of a thickness to assure flexibility of the flaps for assembly purposes.

It is apparent that, within the scope of the invention, modifications and different arrangements may be made other than as herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.

I claim:

1. Switch mechanism, in combination, support means including a plate, an elongated element secured to the plate, a pair of current conducting switch arms, contacts mounted by said arms, a plurality of disks of insulating material mounted on said elongated element, said switch arms having openings to accommodate portions of the adjacent disks whereby said arms are supported in spaced relation by the disks, terminal connectors for said switch arms extending laterally thereof, said terminal connectors having openings to receive portions of the adjacent insulating disks and being in direct contact with the respective switch arms, a thin-walled housing of molded resin arranged to receive the switch mechanism, opposed walls of the housing being formed with slots to receive the laterally extending terminal connectors, a flap portion adjacent each slot integrally connected to the adjacent wall of the housing and being of a dimension rendering the flap flexible to admit the terminal connectors into the slots and to be reflexed to a position in engagement with the terminal connectors to retain the switch mechanism in the housing.

2. Switch mechanism, in combination, support means including a plate, an elongated element secured to the plate, a pair of current conducting switch arms, contacts mounted by said arms, a plurality of disks of insulating material mounted on said elongated element, said switch arms having openings to accommodate portions of the adjacent disks whereby said arms are supported in spaced relation by the disks, terminal connectors for said switch arms, said terminal connectors having openings to receive portions of the adjacent insulating disks and being in direct contact with the respective switch arms, a thinwalled housing of nonmetallic material arranged to receive the switch mechanism, the walls of the housing adjacent the connectors being formed with slots to receive the terminal connectors, a flap portion adjacent each slot and integrally connected to the adjacent wall of the housing, the region of integral connection of the flap portions with the walls being of a dimension rendering the flap portions bendable to admit the terminal connectors into the slots and engage the terminal connectors to retain the switch mechanism in the housing.

3 Switch mechanism, in combination, support means including a cylindrically shaped member, a pair of switch arms, contacts mounted by said arms, a plurality of circular disks of insulating material mounted on said cylindr-ically shaped member, each of said switch arms being formed with an opening, the disks adjacent said arms being formed with tenon portions received in the openings in said switch arms, connector terminals mounted by said disks and in contact with the respective switch arms, thermoresponsive means arranged to influence the position of one of said switch arms, manually adjustable means for adjusting the relative position of the other of said switch arms, and a housing of molded resin enclosing the support means and switch armg and disk assembly, said housing having openings to accommodate the connector terminals, the housing being formed with flap portions integrally connected thereto and distortable to admit the connector terminals into the openings in the housing and secure the housing in switch enclosing position.

4. Switch mechanism, in combination, support means including a cylindrically shaped member, a pair of switch arms, contacts mounted by said arms, a plurality of circular disks of insulating material mounted on said cylindrically shaped member, each of said switch arms being formed with an opening, the disks adjacent said arms being formed with tenon portions received in the openings in said switch arms, the disk below one switch arm and the disk above the other switch arm being formed with outwardly extending peripheral flanges, connector terminals mounted by said disks and in contact with said respective switch arms, thermoresponsive means arranged to influence the position of one of said switch arms, manually adjustable means for adjusting the relative position of the other of said switch arms, a member of insulating material supported on the switch arm influenced by the thermoresponsive means and extending outwardly beyond the edges of the said switch arm, and a housing of nonmetallic material enclosing the support means and switch arms, said housing having openings to accommodate the connector terminals, the portions of said housing adjacent said connector terminals being distortable to admit the connector terminals into the openings in the housing and secure the housing in switch enclosing position.

5. Switch mechanism, in combination, support means including a cylindrical shaped member, a pair of switch arms, contacts mounted by said arms, a plurality of circular disks of insulating material mounted on said cyline drically shaped member, each of said switch arms being formed with an opening, the disks adjacent said arms being formed with tenon portions received in the openings in said switch arms, the disk below one switch arm and the disk above the other switch arm being formed with outwardly extending peripheral flanges, connector terminals mounted by said disks and in contact with said respective switch arms, thermoresponsive means arranged to influence the position of one of said switch arms, manually adjustable means for adjusting the relative position of the other of said switch arms, a strip of insulating material supported on the switch arm influenced by the thermoresponsive means and extending outwardly beyond the edges of the said switch arm, and a comparatively thin-walled housing of molded resin enclosing the support means and switch arms, the walls of said housing adjacent the connector terminals having openings to accommodate the connector terminals, the portions of said hous ing walls adjacent said openings being arranged to be flexed outwardly to admit the connector terminals into the openings in the housing and reflexed inwardly in engagement with the connector terminals.

References Cited in the file of this patent UNITED STATES PATENTS 2,317,083 Daiforn Apr. 20, 1943 2,328,152 Kuhn et a1 Aug. 31, 1943 2,751,466 Huffman June 19, 1956 2,774,846 Lee Dec. '18, '1956 2,892,014 Eichelberger June 23, 1959 

5. SWITCH MECHANSIM, IN COMBINATION, SUPPORT MEANS INCLUDING A CYLINDRICAL SHAPED MEMBER, A PAIR OF SWITCH ARMS, CONTACTS MOUNTED BY SAID ARMS, A PLURALITY OF CIR CULAR DISKS OF INSULATING MATERIAL MOUNTED ON SAID CYLINDRICALLY SHAPED MEMBER, EACH OF SAID SWITCH ARMS BEING FORMED WITH AN OPENING, THE DISK ADJACENT SAID ARMS BEING FORMED WITH TENON PORTIONS RECEIVED IN THE OPENINGS IN SAID SWITCH ARMS, THE DISK BELOW ONE SWITCH ARM AND THE DISK ABOVE THE OTHER SWITCH ARM BEING FORMED WITH OUTWARDLY EXTENDING PERIPHERAL FLANGES, CONNECTOR TERMINALS MOUNTED BY SAID DISKS AND IN CONTACT WITH SAID RESPECTIVE SWITCH ARMS, THERMORESPONSIVE MEANS ARRANGED TO INFLUENCE THE POSITION OF ONE OF SAID SWITCH ARMS, MANUALLY ADJUSTABLE MEANS FOR ADJUSTING THE RELATIVE POSITION OF THE OTHER OF SAID SWITCH ARM A STRIP OF INSULATING MATERIAL SUPPORTED ON THE SWITCH ARM INFLUENCED BY THE THERMORESPONSIVE MEANS AND EXTENDING OUTWARDLY BEYOND THE EDGES OF THE SAID SWITCH ARM, AND A COMPARATIVELY THIN-WALLED HOUSING OF MOLDED RESIN ENCLOSING THE SUPPORT MEANS AND SWITCH ARMS, THE WALLS OF SAID HOUSING ADJACENT THE CONNECTOR TERMINALS HAVING OPENINGS TO ACCOMMODATE THE CONNECTOR TERMINALS, THE PORTIONS OF SAID HOUSING WALLS ADJACENT SAID OPENINGS BEING ARRANGED TO BE FLEXED OUTWARDLY TO ADMIT THE CONNECTOR TERMINALS INTO THE OPENINGS IN THE HOUSING AND REFLEXED INWARDLY IN ENGAGEMENT WITH THE CONNECTOR TERMINALS. 